It could be possible that the Guru's time was our age of pioneering in a way, as they brought ideas that were never heard of in india at the time and slowly introduced the tenents like the one universal creator, langar, gurmukhi, and later the militarization of the panth. If this is true, then that adds another 200 or so years to the empires lifetime. But then again we would have to define the first date we took rule (both spiritually and temporally). Other than that I entirely agree with you.

Well, if for other empires, the stages were spread out over centuries, we compressed the latter 4 stages over less than half a century up to falling before the British.
I think you could say we skipped over the pioneer stage or not really applicable to us, since we were already spread out in the Indian sub-continent.
The 18th century was spent in battles and conquests.
The first half of the 19th century comprised further conquests, and also commerce, affluence, intellect, and decadence. Finally loss of empire to the British.
Many commentators have stated that raj leads to affluence which leads to softness which leads to loss to the enemy. I agree with this.
Also, the Rehit was supposed to keep us hard, but we disregarded Rehit in the time of the Sikh Raj because we had become too enamored of the pleasures of the flesh, fine foods and wines, and beautiful ladies.

Unfortunately, I haven't studied the Sikh Raj enough to bring up examples other than Gulab and Lal Singh. It seems from these cases that promises of power and wealth are the biggest causes of treason in the sikh kaum, as Lal Singh sold off military secrets. Maya seems to be one of the bigger reasons our leadership fails us as they fall into these tricks. Its not just a problem with us but almost all communities.
Having meetings where issues in the panth are deliberated on (Sarbat Khalsa), with the panj pyare in charge, have been the best method of policy making in the kaum and building trust in the leadership. Ranjit Singh abolished this as in his view, they had Khalsa so the meetings were pointless as his ruling party would make decisions. I don't know how much this would in paticular, would have influenced betrayal in the panth but its worth reinsating/organizing on a smaller level. Like maybe, for this site we could have a yearly tick box for things the kaum should do and we can check up on those tasks to see if they are being implemented.

Yes veerji. Note that in the part of my post that you quoted, I acknowledged the great work that Preet Gill has done in parliament. We must make sure that those who stand with us know that we appreciate their efforts.